1. Field of the Invention
The present invention relates to a tape rewinding mechanism for a magnetic recording/reproducing apparatus, and more specifically, to a tape rewinding mechanism, in which, at the time of ejecting the tape from the tape deck, the tape reel that is wound with the tape is driven by a capstan motor, so that a proper tension is maintained between the tape and the drum, thereby preventing damage to the tape.
2. Description of the Prior Art
Many types of video tape recorders are currently known and used in various home electronics equipment. The most common tape recorders/reproducers use a 1/2-inch tape cassette. These magnetic recording/reproducing devices include: a cassette holder receiving a tape cassette; driving members for pulling the cassette holder into the body of the apparatus to place the cassette holder on a main deck; a loading system for loading or unloading the magnetic tape of the tape cassette to and from a rotary drum of the main deck; and a travelling system for making the tape run along a predetermined path.
Further, portable video cameras include the above type of magnetic recording/reproducing devices. Many such video cameras are compact and use an 8 mm tape cassette. One of the most influential factors in determining the compactness of a magnetic tape recorder/reproducer is the size of the tape deck. Basically, the success of reducing the size of a recorder/reproducer depends mostly on the reduction in size of the tape deck.
A recent trend has been towards small lightweight magnetic recording/reproducing devices, such as those which utilize the widely available 8 mm tape cassette. One such small, lightweight magnetic recording/reproducing device is disclosed in Published PCT Application WO9312163, (corresponding to Korean Patent Application 93-5016), which is incorporated herein by reference. As disclosed in the latter publication, the deck size is highly minimized in such a manner that a tape cassette is inserted into a cassette holder having a rotary drum to perform the first loading of a magnetic tape, and the cassette holder is then closed by being pressed to fully load the magnetic tape, wherein the rotary drum is completely held within an internal space of the tape cassette while the loading operation of the tape cassette is completed. According to this apparatus, power is supplied to the travelling system and loading system by means of a single capstan motor, thereby eliminating the need for two motors and reducing the size and weight of the tape deck.
A magnetic recorder/reproducer main deck of the type described in the above mentioned Published PCT Application is illustrated in FIGS. 1A through 1C herein, wherein there is shown a cassette 30 and a rotary drum 12 in various states of loading and unloading. The rotary drum 12 is installed on a main chassis 10. The tape cassette 30, with a tape 32 wound therein, is positioned on a pair of reel hubs on a sub-chassis 20. The sub-chassis 20 is adapted to move horizontally forward and backward on the main chassis 10 to bring the tape 32 into contact (loading) with the rotary drum (FIG. 1B) and to remove the tape 32 from contact with the rotary drum 12. When the tape is loaded, as in FIG. 1B, recording or reproducing operations may be performed.
FIG. 1A shows the condition of the elements mentioned when the tape is first loaded onto the sub-chassis. The tape 32 is presumed to be taut across the cassette opening. When the sub-chassis moves forward relative to the main chassis, the drum loosens the tape so as to cause it to surround the drum partially as shown in FIG. 1B. Subsequent to a recording or reproducing operation, when it is desired to eject the cassette, the sub-chassis is moved in the backward or reverse direction relative to the drum to "unload" the tape. However, as shown in FIG. 1C, this operation results in a loose portion of the tape existing in the cassette opening. Unfortunately, during ejection, the loosened portion of the tape 32 can become entangled with a lid or other components of the deck, causing damage to the tape.
One attempt to solve the latter problem is disclosed in Korean Patent Application (KPA) No. 93-14667. The latter KPA discloses a tape rewinding mechanism using a rack gear and an idler gear, which are shown in FIG. 2 herein. The elements are shown in FIG. 2 in the state just prior to moving the sub-chassis 20, with the tape cassette thereon, toward the main chassis 10. The tape cassette 30 is not shown for clarity of illustration.
As the user pushes the sub-chassis 20 toward the rotary drum 12, a sub-chassis moving mechanism (not shown) takes over and moves the sub-chassis 20 horizontally toward the rotary drum 12. A gear 40 on the sub-chassis is meshed with a rack 42 on the main chassis, resulting in the gear 40 rotating counter clockwise as the sub-chassis moves forward. The gear 44 rotates clockwise, and the gear 44 and the gear 46 rotates counter clockwise. The gear 46 meshes with supply reel 52, which rotates clockwise. The tape is loosened from the supply reel by the clockwise rotation, but is held taut on the drum when loading is completed.
During the horizontal movement of the sub-chassis 20, protuberances 8a and 49a of reel bases 48 and 49 come into engagement with stoppers 10a and 10b, respectively, on the main chassis 10, causing the reel bases to pivot around shafts 48b and 49b in the direction indicated by the arrows A. This pivoting causes the gear 46 to move out of engagement with gear 44. The axial shaft 44a of the gear 44 is positioned at the left portion of an elongate slot 48c of the reel base 48. Under this condition, a loading system (not shown, but including conventional elements, such as a pole base, a pinch arm, a pinch roller and review pole and the like) is activated to fully load the tape onto the drum, so that the reproducing/recording, rewinding, or fast forward operations can be carried out.
After a recording or reproduction operation, when the tape cassette is to be ejected, the loading system is activated so as to unload the tape. The sub-chassis 20 withdraws from the main chassis 10 in the horizontal direction, causing the protuberances 48a and 49a of the reel bases 48 and 49 to disengage from the stoppers 10a and 10b. As a result, the reel bases 48 and 49 pivot in the opposite direction from the arrow marks A due to the elastic force of the spring 50. Accordingly, the gear 44 engages the gear 46, and the movement of gear 40 along track 42 results in the supply reel 52 rotating in the counter clockwise direction to take up the slack of the tape to prevent the situation shown in FIG. 1C.
While the mechanism described solves the problem of loose tape during an eject operation, it does so at the cost of complexity. Namely, a rack has to be installed on the main chassis, and the reel base has to be provided with a plurality of gears. Not only does this complicate the construction of the deck, but it also increases the weight and bulk of the deck.